<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>绝对定位</title>
		<style>
			#d1,#d2,#d3{
				width: 400px;
				height: 100px;
				background-color: darkgoldenrod;
				margin-bottom: 20px;
			}
			#d2{
				background-color: aqua;
				position: absolute;
				left: -40px;
				top:-45px;
			}
		</style>
	</head>
	<body>
		<!-- 屏幕坐标系，横向往右是x正轴，垂直往下是y轴正轴-->
		<div id="d1">111</div>
		<div id="d2">222</div>
		<div id="d3">333sdkfjlsdlkfjsdlkfjsdlfkjsldfkj</div>
	</body>
</html>